A reaction for producing acrylonitrile by reacting propylene with ammonia in the presence of molecular oxygen is known as “ammoxidation reaction”, and this reaction is used as a method for industrially producing acrylonitrile.
In this reaction, an oxide catalyst is utilized for achieving a favorable acrylonitrile yield. For example, a catalyst containing Mo—Bi—Fe or Fe—Sb as essential components is industrially used. Catalysts obtained by adding additional elements to the above-described essential components in order to achieve a further favorable acrylonitrile yield are also known (see, for example, Patent Literatures 1 and 2).
On the other hand, attempts to improve the acrylonitrile yield by not only improving a metal composition but also improving a catalyst preparation step have also been made. For example, Patent Literatures 3, 4 and 5 describe a method for preparing an ammoxidation catalyst containing molybdenum, bismuth, and iron as essential components, in which a carboxylic acid is added to a starting material slurry.